ERI and voltage

My pacemaker is 11, almost twelve, years old. We've been doing more frequent checks for about a year. At the most recent in-office check a couple of weeks ago, I was told my pacemaker is now in ERI because the voltage is at 2.6v, although the estimated battery still reads 2-3 months. 

Although I've noticed voltage increasing in the last year or so, I'd never thought to question its significance to ERI. But now I'm curious. What is voltage telling us?

Also, although no mention of the need for it was made during the pacemaker check appointment, my EP has ordered an echocardiogram. Again, I am wondering about the significance. Does an increase in voltage suggest a possible change in the heart's (rather than the pacemaker's) function?


5 Comments

ERI

by Tracey_E - 2022-06-28 11:16:21

I don't understand the specifics, but I know they watch for the spike in voltage to tell them it's ERI. ERI means 2-3 months left, that's why it's still elective replacement. Get it done now if you can, EOS doesn't feel good. I don't think it has anything to do with the condition of our heart, it's all about the battery. 

Getting an echo before is normal, esp if you haven't had one in a while. It doesn't mean they think something is wrong, they just want to confirm your function is what they think it is. If our function has dropped enough to discuss adding a third lead, this is the time to do it. 

ERI

by AgentX86 - 2022-06-28 13:35:59

A Tracey says, if you can, do it now.  ERI == Elective Replacement Indicator.  It means that it should be replaced but it's not a necessity.  Yet.  This is supposed to be three months before the EOL flag, at which point it shuts down all features other than fixed rate pacing (AOO or VOO). You don't want to be End of Life ;-). 

We say, if you can because insurance or whoever is really paying the bills may think that it's still "elective surgery".  All they're doing by kicking the can down the road is exactly that.  Pay now or pay in 90 days with interest.

As far as the voltage, as an EE I don't even care.  It's almost impossible to tell anything useful by measuring the battery voltage of most battery chemistries.  The voltage change for lithium-based batteries is very (very) small until just before the run out of gas.  Even then, the absolute voltage doesn't mean a lot.  You'd have to track the voltage for some time to see the trend as it starts to discharge.  When it's noticed, it doesn't have much left in the gas tank.  Before that, it's just a SWAG.

Push for it now, or at least in the next 30 days.

I hope you transition to a new device painlessly dear Gotrhythm

by Gemita - 2022-06-29 09:13:11

Hello Gotrhythm, I just wanted to wish you well as you get closer to having your device change.  I am just 4 years into my pacing experience, so I hope I get as many years out of my device as you have.  

I would agree that an echo at this time would seem sensible to have a good look at your heart function.  Depending on the results of your echo, they might decide to upgrade your device, perhaps even to choose a different manufacturer.  Echo results might also help them to make any necessary adjustments to new device settings in the future, to give you a better experience from the start.  I would make sure you know what your old settings are though, unless they automatically transfer them over to the new device?  

I would imagine too it is helpful to get an echo done as we approach end of battery life to see how well our heart copes as battery function declines.  Clearly if there are signs of diminished heart capacity, then the case for early replacement/upgrade would become more pressing.  

Fluctuations in voltage/related settings.  What is this telling us?  Apart from battery drain, if I understand your question correctly, I wonder too if it is suggesting that we are needing more power to effectively pace the heart with say a falling ejection fraction or some other acute illness, or perhaps that the heart needs more pacing support during periods of rhythm disturbances?   Of course fluctuations in our numbers might be seen for any number of reasons, from poor lead contact, lead position to signs of lead failure. So many things could affect our pacing requirements, including the medication we take and our activity level.  

Update

by Gotrhythm - 2022-06-30 13:42:35

Thanks for the info guys. Tracey had it right. The echo is standard prep for replacement.

AgentX86, your explanation of what voltage has to do with ERI was enlightening and makes perfect sense of why the NP would declare ERI, regardless of estimated battery.

Gemita, your calm, gentle good sense comes through no matter what you're talking about. It's always comforting.

The echo experience itself was delightful. Early on, I remarked that whoever first looked at an echo and could make sense of anything was the smartest person in the world. 

When the young tech realized I was interested she began telling me about the development of the echo technology's application to cardiology, pioneered at Duke, and explaining what she was looking at. She showed me the pacemaker wire in the ventricle (and yes, you can see it moving!) aortia--descending and ascending, and all sorts of other interesting landmarks. She told me how a transplanted heart, or one with CBBG or other procedures might look different, and she remaked that my heart took very good pictures.

A photogeninc heart. Who knew there was such a thing, or that I had one!

Thanks again to everyone for all your help and support.

ignore estimated life

by dwelch - 2022-07-09 08:05:40

As a general rule ignore estimated life of the device.  It gets you in the ball park (last year or two, even if it says many years or a few months).  Also as an EE the battery level is not a great indicator, at best also a rough idea more than an accurate measuring tool.

If you are in ERI you could/should feel it.  Mine have locked me at 65BPM and climing the same stairs at work that I climb every day.  Yeah had to make stops to get up them then just used the elevator until after the next device.

Seems like insurance now wants to put you in this mode.  Docs would allow for replacement sooner based on estimated life and battery, but insurance wants to squeeze out those extra months/year across all the patients to save money, so now this is the trigger.  The device is trying to keep you going another few months.

Now yes, the device is using a not that accurate measuring stick to make that switch, the doc could reset it back to a normal mode and the device may stay normal for a bit (days/weeks) and then decide to go back into this mode.  And maybe some day insurance will force us to ride this mode for a month or so. 

But this is the indicator, its time, you have been through this at least once before, so you know what to expect.  The next device might be smaller and will have better tech. (im on my fifth device).  Get your heavy lifting done, some easy to put on clothes ready, tell work you will be out for a week or few, etc...Talk to the doc about the activities that you do or want to continue to do so they can choose your next device.

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